Re: [PATCH v5 0/8] media: Introduce V4L2 generic ISP support

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Jacopo,

On Mon, Sep 15, 2025 at 07:18:09PM +0200, Jacopo Mondi wrote:
> Extensible parameters meta formats have been introduced in the Linux
> kernel v6.12 initially to support different revision of the RkISP1 ISP
> implemented in different SoC. In order to avoid breaking userspace
> everytime an ISP configuration block is added or modified in the uAPI
> these new formats, which are versionated and extensible by their
> definition have been introduced.
> 
> See for reference:
> e9d05e9d5db1 ("media: uapi: rkisp1-config: Add extensible params format")
> 6c53a7b68c5d ("media: rkisp1: Implement extensible params support")
> 
> The Amlogic C3 ISP driver followed shortly, introducing an extensible
> format for the ISP configuration:
> 
> 6d406187ebc0 ("media: uapi: Add stats info and parameters buffer for C3 ISP")
> 
> with a very similar, if not identical, implementation of the routines to
> validate and handle the ISP configuration in the ISP driver in the
> c3-isp-params.c file.
> 
> fb2e135208f3 ("media: platform: Add C3 ISP driver")
> 
> With the recent upstreaming attempt of the Mali C55 ISP driver from Dan,
> a third user of extensible parameters is going to be itroduced in the
> kernel, duplicating again in the driver the procedure for validating and
> handling the ISP configuration blocks
> 
> https://patchwork.linuxtv.org/project/linux-media/patch/20250624-c55-v10-15-54f3d4196990@ideasonboard.com/
> 
> To avoid duplicating again the validation routines and common types
> definition, this series introduces v4l2-isp.c/.h for the kAPI
> and v4l2-isp.h for the uAPI and re-organize the RkISP1
> and Amlogic C3 drivers to use the common types and the helper validation
> routines.
> 
> The v4l2-isp abstraction will be augmented to support statistcs as well.
> 
> If the here proposed approach is accepted, I propose to rebase the Mali
> C55 driver on top of this series, to use the new common types and
> helpers.
> 
> I have been able to test this on RkISP1 but not on C3.

Thank you for working on this.

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Kind regards,

Sakari Ailus